Valence Shell Configuration (2.55)

[Faisal Alshamaa - 1L]

Hello,

What is the valence shell configuration and how is it different than the ground state electron configuration (if it is any different at all)?

Thanks!

[Kaleb Tesfaye 1I]

Valence shell configuration is basically just the outermost shell of an atom. These are the electrons that are usually involved in bonding and reactions. The number of valence shell electrons is usually determined by the position of the atom in the periodic table. Atoms in Group 1 have 1 valence electron, the ones in group 2 have 2, the ones in group 13 have 3, group 14 have 4, group 15 have 5, group 16 have 6, group 17 have 7, and group 18 have 8. The elements between group 3-12 are a bit more complicated. And elements with 8 valence electron are unreactive (the noble gases). Valence electrons only involve the s and p orbitals so the maximum number of valence electrons you can have is 8 (2 in the s orbital and 6 in the p orbital).

Ground state electron configuration, on the other hand, is the electron configuration of an atom with all its electrons. This means, it will involves all of the orbitals in the atom and describes the configuration of the atom when it is not a cation/anion.

for example, the ground state configuration for Chlorine is [Ne]3s^2 3p^5. But the valence electron configuration is just the outermost shell so it would be 3s^2 3p^5. Therefore, Chlorine has 7 valence electrons.

[004985802]

ground state electron configuration accounts for all electrons in the atom at its non ionized state, while valence electrons/diagrams only account for the electrons in the outer orbitals of the atom (at an ionized or ground state)